Stories from the Biomes: moving the outdoor plants
From the beginning of the Biomes project the outdoor horticulture team have been hard at work preparing and moving plants to facilitate the work on the Glasshouses. New paths have been created so the visitors can still access the collections and enjoy the Garden. Access routes have been widened so contractors can get large vehicles on site to carry out the essential works. And new beds have been made to rehome the moved plants.
Contractors onsite in November 2021 widening the road outside the Palm Houses for large vehicle access.
Moving trees, shrubs and herbaceous plants
The process of digging plants out of the ground reduces the root structure so they are less able to uptake water. The plants are pruned back reducing the canopy, this means the plants will need less water to establish. The principle of this method works no matter the size of the plant, from a small herbaceous plant to a huge tree, they both take water up through the roots and transport it to the leaves.
Bergenia cordifolia planted in a new bed in the West Border in August 2021. The large leaves have been removed to reduce transpiration, the process of water leaving the leaves through tiny holes on the underside of the leaf.
Herbaceous plants and small shrubs which can be dug out and lifted by hand are transported in wheelbarrows. Whereas larger shrubs and trees are too heavy to lift by hand so they are dug around creating a trench circling the root ball then a tractor is used to scoop them up and transport them across the garden. It is important that plants are out of the ground for as little time as possible so planning ahead and preparing the beds is an important part of the job.
Rhododendron x sochadzeae, wild collected in Turkey in 1962, moved in autumn 2021 to allow a path to be widened for access, is lowered into the planting hole by the tractor.Hakea megadenia, wild collected in Tasmania in 2010, has been dug around by hand then is scooped up by the tractor. This plant was growing over a heating duct just outside the front range glasshouse. Moving it was particularly tricky, we hoped it would survive in the slightly cooler soil out in the Garden. Hakea megadenia in flower and thriving out in the garden after being moved earlier in the year. Rhododendron ‘Coronation Lady’, moved from the Azalea lawn so a path could be widened for access, has been pruned back and is lowered into a planting hole. A group of these Rhododendrons now live on the path leading to the John Hope Gateway from the Herbaceous Border.Rhododendron griersonianum’s root ball has been wrapped to keep the roots moist and the soil in place while it travels across the Garden on a particularly sunny day in October 2021. Rhododendron griersonianum is lowered into a planting hole by the tractor, burlap and hessian protect the roots. This Rhododendron now lives next to Inverleith House by the path to the secret garden.Sorbus japonica, wild collected in Japan, was moved from right next to one of the Glasshouses. It is transported on a telehandler, a nimble bit of machinery that can maneuver in the small space between two glasshouses.
The after care of the plants
The plants that have been moved require a little more TLC than the rest of the outdoor collections, they are closely monitored for signs of ill health, drought, pests or disease.
The larger plants need a bit of extra help to stabilise them while the roots establish. Edinburgh can get very windy, so if a tree or shrub has not had the time to put anchor roots down in its new home, it could be blown over. There are two main types of help, a wooden stake for the smaller trees and shrubs and metal guy ropes for the larger trees.
Sorbus japonica planted in a newly created bed within a Japanese planting area, metal guy ropes will help stabilise it while the roots establish. Ovidia pillopillo, wild collected in Chile in 2013, was moved from next to the Front Range Glasshouse and replanted in the new Chilean planting area. Stabilised with a wooden tree stake until the roots properly establish.
A very important part of the after care of moved plants is watering. This year has been particularly dry throughout winter and summer with a heatwave in July. This has left the ground very dry and the plants very thirsty. As a result, the rain dampens only the top layer of soil making it look wet, but the water is not penetrating deeper where the roots are, so it is important to check the soil and irrigate even when the weather is wet.
In this image the darker top layer of soil looks wet, however, remove the top layer and the paler ground underneath is very dry. Seep hose coiled round Blechnum magellanicum a fern wild collected from Chile in 2012. Seep hoses disperse the water through lots of tiny holes exactly where it is needed at a slow rate, so the bed does not flood and water is not unnecessarily lost.A group of Rhododendron ‘Coronation Lady’, moved from the Azalea lawn so a path could be widened for access, has a seep hose placed throughout the bed to provide much needed water to the roots during the hot summer weather. Sorbus japonica putting on healthy new growth as spring arrives.Sorbus japonica detail of new growth and flowers.
